Self-loading scraper with cleaning shield for the blades

ABSTRACT

A self-loading earthmoving scraper having a scraper bowl provided with a loading device carried by the front end of the bowl above the scraper blade. The loading device has a plurality of paddles supported for orbital movement about a transverse horizontal axis and is adapted to be driven in a direction to load material cut by the scraper blade into the bowl. Each of the paddles is provided with outwardly projecting means formed on the rear surface of the paddle that cooperate with the ejector for discharging material out of a bowl.

iliiiied Etaiea Wateiii [151 9,099,355 Eiger 1 Feb. 22, 11972 [54] SElLlF-ILUAMNG SCRAPER Wll'llllil 3,474,548 10/1969 Miller ..37/8

iZlLlEANllNG Si-IIKELD FUR THE BLADES 3,525,167 8/1970 French et al ..37/8

[72] Inventor: William ill. Eiger, Eastlake, Ohio [73] Assignee: General Motors Corporation, Detroit,

Mich.

[221 Filed: Nov. 25, 119159 [21] Appl. No.: 979,657

[52] US. Cl ..37/4l, 37/8, 37/126,

[51] llnt. Cl. .Bfillp 11/00, B60p 1/36 [58] Field of Search r ..37/4, 5, 6, 7, 8, 126, 129; 198/10,12, 212

[56] Reierences Cited UNITED STATES PATENTS 2,844,892 7/1958 Carston ..37/4

Primary ExaminerRobert E. Bagwill Assistant Examiner-R. T. Racler Attorney-4. L. Carpenter and E. J. Biskup [57] ABSTRACT A self-loading earthmoving scraper having a scraper bowl provided with a loading device carried by the front end of the bowl above the scraper blade. The loading device has a plurality of paddles supported for orbital movement about a transverse horizontal axis and is adapted to be driven in a direction to load material cut by the scraper blade into the bowl. Each of the paddles is provided with outwardly projecting means formed on the rear surface of the paddle that cooperate with the ejector for discharging material out of a bowl.

1 Claim, 6 Drawing Figures EDE QBEEE PNWWHFEBW m2 SHEET 1 BF 4 ATTORNEY PATENTEDFEB 22 lm SHEET M [1F 4 ATTORNEY SlELlF-LOAIDKNG SClitAllEllt Wli'llii CLEANING Sll-llIlElLD lFUllt THE BLADES The present invention concerns a self-loading scraper having a loading device which can be used as an accessory in scraper bowls employing conventional ejector systems which discharge material out of the mouth of the bowl. The invention is particularly useful in cases where a rollout type ejector, as seen in US. Pat. Bernotas et al. No. 3,466,765, is incorporated in the scraper bowl in that means are formed with the loading device for facilitating unloading by cooperative action occurring between the paddles of the loading device and the ejector plate. In addition, the loading device, which forms a part of this invention, has a dirt shield which has the dual function of cleaning the paddles as they are being rotated during a loading operation and also serving as a material confiner so as to permit positive displacement-type loading with a minimum of material being thrown forwardly out of the bowl as commonly occurs with self-loading elevating scrapers.

The objects of the present invention are to provide a selfloading scraper having a loading device including a plurality of paddles supported for orbital movement and adapted to be driven in one direction to load material cut by the scraper blade into the bowl and having means formed thereon which cooperated with the ejector for discharging material out of the bowl when driven in the opposite direction; to provide a loading device for the front end of a scraper that is normally located adjacent the cutting blade and cooperates therewith for loading material into the bowl and includes a shield which prevents material from being thrown forwardly of the scraper during operation of the loading device; to provide a loading device for a scraper that has orbiting paddles which are inclined forwardly and adapted to be driven in an orbiting path while maintaining the same inclined position and cooperated with a shield located above the path of travel of the paddles for positive displacement of material cut by the cutting blade into the bowl; to provide a loading device which assists loading material into a scraper bowl and includes orbiting paddles, each of which has the rear surface thereof formed with projecting members which serve to engage and move material out of the scraper bowl during the ejection operation; to provide a shield for a scraper loading device which cooperates with the rear surface of the rotatable material engaging parts of the loader for removing any material which may be clinging thereto; and to provide a mechanism which can be mounted as an accessory at the front end of a scraper bowl and has at least two transversely extending paddles which are adapted to be driven in an orbital path about a transverse axis and are combined with a shield which serves to wipe the ground-engaging surface of the paddles clean on their upswing so as to prevent the paddles for carrying material out of the bowl.

ln the preferred form, the above objects and others are accomplished with an earthmoving scraper which includes a tractor and a trailing scraper bowl, the latter of which has an open front defined by a pair of laterally spaced sidewalls, A horizontal scraper blade extends transversely between the lower ends of the sidewalls and an ejector is located in the rear of the bowl for discharging material out of the front end of the bowl. A loading device is carried by the bowl above the scraper blade and is supported for movement between a lowered position which constitutes the normal operating position for the loading device, and a raised position which permits the front end of the bowl to be opened so that material can be discharged therefrom. The loading device is characterized in that it includes at least two paddles which are carried on transverse shafts located at diametrically opposed points and is provided with means for maintaining the paddles at a fixed inclined attitude relative to the ground while being rotated about a transverse horizontal axis. Means are provided for driving the paddles in opposite directions so that the material cut by the scraper blade can be moved toward the rear of the bowl and also for aiding removal of the material out of the bowl. In this regard, the rear or ground-engaging surface of each paddle is formed with outwardly extending projections which do not interfere with the loading ability of the device but serve as claws for engaging the material being moved by the ejector out of the bowl so as to facilitate such operation. An added feature of the loading device is the use of a shield member which is mounted for movement with the loading device between the aforementioned raised and lowered positions. The shield has a free end which is preferably curved and positioned so that it is in wiping contact with the rear ground-engaging surface of the paddle. As a result, any material which may cling to the paddle during a loading operation is removed therefrom so as to preclude it from being carried forwardly out of the bowl.

Other features and advantages of the invention will be more apparent from the following detailed description when taken with the drawings in which:

FIG. 1 is an elevational side view showing an earthmoving scraper incorporating a loading device made in accordance with the invention;

FIG. 2 is a plan view of the loading device taken on line 2- 2 of FIG. 11;

FIG. 3 is an enlarged view partly in section of the drive mechanism incorporated with the loading device and taken on line 3-3 of FIG. ll;

FIG. 4 is an enlarged elevational view with certain parts broken away and showing the loading device of FIG. 3;

FIG. 5 is a rear view of the loading device taken on line 55 of FIG. 2; and

FIG. 6 is a view showing the loading device in a raised position and cooperating with the ejector for discharging the load out of the scraper bowl.

Referring to the drawings and more particularly FIGS. 1 and 2 thereof, a self-loading scraper is shown comprising an overhung tractor 10 connected to a trailing scraper bowl 12 by the usual gooseneck 14 that extends rearwardly for rigid connection with a transverse torque tube llo. As seen in FIG. 2, the opposite ends of the torque tube 16 are rigidly attached to rearwardly extending pull arms 18 and 20, the free ends of which are connected ti the bowl by universal ball connections 22 and 24.

The material-retaining portion of the trailing bowl 112 consists of laterally spaced sidewalls 26 and 28 between which an ejector 30 is hinged at its forward end adjacent a transverse cutting blade 32 for rotation about a transverse horizontal axis passing through a pivot connection 34. The ejector 30 is L' shaped and has a floor portion 36 for supporting the material loaded into the bowl during a digging operation. The ejector also includes an integrally formed back portion 38 behind which is located a suitable ejector operating mechanism consisting of a multistage hydraulic cylinder 40 which upon expansion causes the ejector 30 to move forwardly above the pivot connection 34 to dump a load out of the open front end of the scraper bowl. As is conventional, a bowl control mechanism 42 is mounted on the gooseneck and is connected to the front end of the scraper bowl 12 for purposes of raising the latter between a lowereddig position, as seen in FIG. ll, and a raised-carry position.

The front end of the scraper bowl 12 is provided with a loading device 44 which serves to aid the loading of the scraper bowl during a digging operation. To this end, it will be noted that the loading device 44 includes a pair of opposed paddles 46 and 48 that extend transversely between the sidewalls 26 and 28 and are connected to a suitable gear mechanism which causes the paddles 46 and 43 to follow an orbital path about a horizontal drive shaft 50. The opposite ends of the drive shaft 50 are rotatably supported by side arms 52 and 54 which are located outboard of the sidewalls 26 and 28 and are pivotally connected thereto by pivotal connections 56 and 58. The forward ends of the side arms 52 and 54 are rigidly interconnected by a tubular crossmember 60 which adds rigidity to the structure and more importantly serves to ensure that the entire loading device 44 is raised as a unit by double-acting hydraulic cylinders 62 and. 64, each of which is connected by pivotal connections 66 and 68 to the associated side arm and sidewall, respectively. As seen in FIG. 1, the loading device 44 is in the normal position and upon expansion of the hydraulic cylinders 62 and 64 can be raised to the full line position shown in FIG. 6.

The gear mechanism for driving the paddles 46 and 48 of the loading device 44 is best seen in FIGS. 3 and 4 and includes the drive shaft 50, the opposite ends of which rigidly support ring members 70 and 72. The ring members 70 and 72 are splined to the inner ends of axially extending stub shafts 74 and 76 which, in turn, are fixed with lever arms 78 and 80, respectively. The stub shafts 74 and 76 are rotatably supported by bearings 82 and 84 within end housings 86 and 88 fixedly attached to the side arms 52 and 54, respectively. Each end housing 86 and 88, at the inner end thereof, is splined to a nonrotatable gear 90 and serves as a support for an oblong closed casing 92 which extends in opposed directions radially outwardly from the shaft 50 and is rigidly connected to the associated ring member by a plurality of bolts, one of which is identified by reference numeral 93. The casing 92 is adapted to rotatably support axially aligned end shaft members 94 and 96 rigidly formed with the opposite ends of each paddle 46 and 48. In this regard, it will be noted that each casing 92 rigidly supports sleeve members 98 and 100 at diametrically opposed points. The sleeve members 98 and 100 accommodate the shaft members 94 and 96, respectively, which are rotatably supported by bearings 102 and 104. The shaft member 96 of each paddle is splined to a gear 106 having a pitch diameter which is the same as the pitch diameter of the gear 90 carried by the end housing 86. A chain 107 is entrained about the two gears 90 and 106 so that upon rotation of the shaft 50 the casing 92 is rotated and causes each paddle 46 and 48 to move therewith while maintaining a fixed inclination relative to the ground as seen in FIG. 4. Thus, in a sense, a planetary-type gear system with a ratio of 1:1 is provided which causes the gear 106 and, accordingly, the paddle to rotate about the longitudinal center axis of shaft members 94 and 96 and at the same time orbit about the shaft 50.

In operation, the loading device 44 is driven by a pair of double-acting hydraulic cylinders 108 and 110, each of which has the cylinder end connected by a pivotal connection 112 to a side arm while the piston rod end is connected by a pivotal connection 114 to one of the lever arms of the gear mechanism. It will be noted that, as seen in FIG. 4, the pivotal connections 114 of the hydraulic cylinders 108 and 110 are located approximately 90 out of phase on the lever arms 78 and 80 and by properly supplying fluid to one end of each cylinder while venting the other end, the hydraulic cylinders 108 and 110 are able to rotate the drive shaft 50. Although not show, this is accomplished through a suitable hydraulic circuit which includes a fluid directional control valve controlled by a switching device 115 positioned at and actuated by the rear end of each hydraulic cylinder. Thus, as seen in FIG. 4, when the hydraulic cylinder 108 is expanding for rotating the casing 92 in a counterclockwise direction, the hydraulic cylinder 110 will also be expanding for a predetermined amount of angular movement of the casing and after pivotal connection 114 thereof passes over dead center, the switching device 115 will reverse the flow of fluid to the hydraulic cylinder 110 so that the piston rod end of the cylinder will be supplied with pressurized fluid causing contraction thereof so that both hydraulic cylinders 108 and 110 work together for driving the loading device 44. It should be apparent that a similar reversal of fluid flow will occur in the case of both hydraulic cylinders 108 and 110 each time the pivotal connection 114 passes over dead center so that the drive shaft 50 is continuously rotated in a given direction.

It will be noted that as the lever arms 78 and 80 are being rotated in a counterclockwise direction, the stub shafts 74 and 76 cause similar rotation of the drive shaft 50 which, in turn, drives the casing 92 on each side of the paddles 46 and 48. As each casing 92 rotates about the gear 90, the gear and chain arrangement causes the paddles 46 and 48 to maintain a fixed angle of approximately 23 relative to a vertical plane passing through the longitudinal center axis of the paddle.

Mun

Operation of the loading device 44 occurs when the scraper is placed in the lowered-dig position shown in FIG. 1. At such time, the hydraulic cylinders 62 and 64 are placed in a float position and the scraper bowl 12 is lowered by the bowl control mechanism 42 until the cutting blade 32 reaches the desired depth of cut. As the scraper bowl 12 proceeds in the cut, material is loosened by the cutting blade 32 and forced into the bowl by the forward motion of the scraper. With the loading device 44 being driven by the pumping action of the hydraulic cylinders 108 and 110, the paddles 46 and 48 orbit about the drive shaft 50 in an counterclockwise direction as seen in FIG. 1. Thus, as the scraper moves in the cut, the paddles 46 and 48 successively engage the material flowing upwardly from the cutting blade 32 and move it rearwardly into the scraper bowl 12. In order to assure that the paddles 46 and 48 do not cause material to be thrown forwardly out of the bowl, a shield 116 is provided above the paddles. As seen in FIG. 2, the shield 116 extends transversely between and is rigidly connected at its side edges to the side arms 52 and 54 while the front end of the shield is rigidly attached to the crossmember 60. The rear portion 117 of the shield 116 curves downwardly and is formed with three uniformly spaced slots 118, 120 and 122 for purposes which will be explained.

The lower rear portion 117 of the shield 1 16 is positioned so as each paddle 46 and 48 is on its upswing movement, the rear surface of the paddle is cleaned by the wiping action of the rear portion 117 of the shield. In further explanation of this feature, it will be noted that as seen in FIG. 4, each of the paddles 46 and 48 takes the form of a teardrop in cross section having an upper curved part 126 connected with front and rear walls 128 and 130, respectively, which converge at a lower pointed end 132. The rear wall 130 of each of the paddles 46 and 48 has outwardly triangular projections 134, 136 and 1 38 which are rigidly attached thereto and located in equally spaced vertical planes which are normal to the longitudinal axis of each of the paddles 46 and 48. The projections 134, 136 and 138 are spaced along the longitudinal length of each paddle, a distance equal to the distance between the slots 118, 120 and 122 formed in the shield 116. As a result, when each paddle moves into wiping position adjacent the rear portion 117 of the shield 116, as seen in FIG. 6, the projections 134, 136 and 138 register with the slots 118, 120 and 122 and permit the rear wall 130 to be cleaned without any interference between the shield and the projections.

From the above, it should be apparent that the shield 116 permits the loading device 44 to function essentially as a positive displacement device in that material loss during a loading operation is minimized. As a consequence, the volumetric efficiency of the scraper is increased while the surcharge buildup in front of the cutting blade 32 is decreased. Moreover, the projections 134, 136 and 138 formed on the rear wall 130 of each paddle serve an important function during an ejection operation. In this regard, it will be noted that as seen in FIG. 6, when the load is to be dumped out of the front end of the scraper bowl 12, the loading device 44 is raised by the hydraulic cylinders 62 and 64 so as to assume the raised position shown. Thereafter, the hydraulic cylinder 40 is expanded causing the ejector 30 to be raised about its pivot connection 34 to the phantom line position. At the same time, the paddles 46 and 48 are driven in an opposite direction or clockwise so that the projections 134, 136 and 138 on each paddle move successively into engagement with the material and aid ejection thereof. This is an important feature of this invention and is particularly useful in the case of the rollout-type ejector incorporated with the scraper bowl 12. It will be understood, however, that other forms of ejectors can be utilized and still realize the advantages of having the projections on the paddles as described above.

As alluded to hereinbefore, the hydraulic cylinders 62 and 64 connected between the loading device 44 and the scraper bowl are maintained in a float position when the scraper is being loaded. As a result, the loading device 44 is able to pivot freely as a unit about the pivotal connections 56 and 58 while the paddles 46 and 48 are being driven in the loading direction. it has been found that placing the hydraulic cylinders s2 and its in a float position during operation of the loading device M permits the latter to automatically seek an optimum loading height relative to the cutting blade 32 so that drawbar horsepower requirements are reduced and loading of 5 the scraper bowl l2 is facilitated.

Finally, it will be noted that although double-acting reciprocating piston-type hydraulic cylinders 111th and lllltl are shown being used for driving the loading device M, other forms of drive motors can be used for the same purpose. For example, a rotary hydraulic motor can be substituted for each hydraulic cylinder M118 nd lit or, for that matter, an internal combustion engine can be used as the power source and be connected to the gear mechanism of the loading device 414 through a suitable torque converter and transfer case Various changes and modifications can be made in this construction without departing from the spirit of the invention. Such changes and modifications are contemplated by the inventor and he does not wish to be limited except by the scope ofthe appended claims.

lclaim:

l. A self-loading earthmoving scraper including a tractor and a trailing scraper bowl, said how] having an open front defined by a pair of laterally spaced sidewalls interconnected at the upper ends thereof by a crossmember, a horizontal scraper blade extending transversely between and rigidly connected to the lower ends of the sidewalls, mi ejector located in the bowl and pivotally connected to the sidewalls thereof adjacent the scraper blade for discharging material out of the open front end of said bowl, a loading device carried by the bowl and comprising a pair of side arms pivotally connected at the rear ends thereof to said sidewalls, said loading device including a plurality of paddles supported by said side arms above the scraper blade for orbital movement at a fixed attitude about an axis substantially parallel to the longitudinal axis of the scraper blade and adapted to be driven in one direction to load material cut by said scraper blade into said bowl, a pair of double-acting hydraulic cylinders pivotally connected between said sidewalls and said side arms for raising said loading device from a first position wherein said loading device substantially closes the open end of the bowl to a second position wherein the loading device is located above the bowl so as to allow sufficient space for the ejector to discharge material out of the open front end of the bowl, each of said paddles having a front wall and a rear wall the latter of which engages material cut by said scraper blade and serves to push the material into the bowl when said loading device in in the first position and driven in said one direction, a shield enclosing the upper portion of said loading device and extending transversely to the longitudinal axis of the scraper, said shield having a front portion and a rear portion, said front portion being secured to the cross member and having side edges rigidly secured to said arms, said rear portion being of a tran verse length substantially equal to the distance between said arms and extending rearwardly and downwardly into said bowl and being located in a fixed position in the path of movement of the rear wall of each of said paddles so that said rear wall is cleaned by the rear portion and thereby cooperates therewith for loading material into the bowl as the loading device is driven in said one direction.

=l =l= =l a 

1. A self-loading earthmoving scraper including a tractor and a trailing scraper bowl, said bowl having an open front defined by a pair of laterally spaced sidewalls interconnected at the upper ends thereof by a crossmember, a horizontal scraper blade extending transversely between and rigidly connected to the lower ends of the sidewalls, an ejector located in the bowl and pivotally connected to the sidewalls thereof aDjacent the scraper blade for discharging material out of the open front end of said bowl, a loading device carried by the bowl and comprising a pair of side arms pivotally connected at the rear ends thereof to said sidewalls, said loading device including a plurality of paddles supported by said side arms above the scraper blade for orbital movement at a fixed attitude about an axis substantially parallel to the longitudinal axis of the scraper blade and adapted to be driven in one direction to load material cut by said scraper blade into said bowl, a pair of double-acting hydraulic cylinders pivotally connected between said sidewalls and said side arms for raising said loading device from a first position wherein said loading device substantially closes the open end of the bowl to a second position wherein the loading device is located above the bowl so as to allow sufficient space for the ejector to discharge material out of the open front end of the bowl, each of said paddles having a front wall and a rear wall the latter of which engages material cut by said scraper blade and serves to push the material into the bowl when said loading device in in the first position and driven in said one direction, a shield enclosing the upper portion of said loading device and extending transversely to the longitudinal axis of the scraper, said shield having a front portion and a rear portion, said front portion being secured to the cross member and having side edges rigidly secured to said arms, said rear portion being of a transverse length substantially equal to the distance between said arms and extending rearwardly and downwardly into said bowl and being located in a fixed position in the path of movement of the rear wall of each of said paddles so that said rear wall is cleaned by the rear portion and thereby cooperates therewith for loading material into the bowl as the loading device is driven in said one direction. 